Monday, July 14, 2008

Genetics and Dogs or…HELP FIDO’s DNA Study

This week there has been quite a buzz in the news about a recent study from the University of Pennsylvania on canine aggression. Brent Toellner over at KCDogBlog did a great write up on it that, if you haven’t read, you should do so now! A major problem that I have with the whole story, as covered by the media, is that the study has yet to be published. As far back as May of this year you can find references to it being published “this week” in the Applied Animal Behavioral Science journal. However, I have access to journals and I can tell that even in the upcoming August edition it does not appear. I am a HUGE believer in reading the actual science article in a peer reviewed journal before I form an opinion. Unlike many of our elected officials…I believe in getting my facts from the source and not from a media account.

But I digress.

From what I can discern from the limited information available so far about this study, it shores up what many anti-BSL advocates have been saying for a long time…you cannot create policy based solely upon the breed of a dog because breed means little. You MUST evaluate each and every dog on its individual behaviors. Genetics has always fascinated me. In my former “day job” position at a Columbus healthcare system I managed the Cancer Genetic Counseling program. Being a young cancer survivor, I was tested early on for a genetic mutation associated with breast cancer. I tested negative, however because I had great counseling I understand that this does not mean I don’t have some sort of familial condition that might have put me at risk. In other words, as much as has been learned about genetics…the unknown is far greater. That is how I came to be interested in canine genetics and the various breed tests and mixed breed “panel” tests that are currently being marketed.

Then a story aired on “60 Minutes” about human genetics and ancestor discovery. A key point made in this story is that you don’t have to go back very far in your own pedigree to see that one individual can have multiple influences such that it is nearly impossible to nail down where you “came from.” For every generation your DNA sources double: 4 grandparents, 8 great-grandparents, 16 great great-grandparents, 32 great great-grandparents…you get the picture. In case you don't - if you go back just 20 generations you have more than one million grandparents!!

Along those lines, HELP FIDO has embarked on a research study looking at breed identification subjectively and with DNA. The hypothesis is that, absent a pedigree, one cannot determine with any consistent accuracy the predominant breed of any one dog. Therefore, it is unconscionable to set policy based on a breed rather than behavior, because the penalty of being wrong is a death sentence for the dog in question.

We are doing this by collecting DNA results, photos, and narratives from owners of dogs of any breeds (with a focus on those dogs determined to be bully breeds). One outcome of this project will be to analyze how DNA results correlate with previously put-upon breed determinations. A perfect example of this comes from Jennifer Thomas over at happypitbull.com. She posted a story about her DNA test results for Dozer and I commented back about our study, shamelessly soliciting for her results, which she has generously supplied. Reprinted here with her permission is some fascinating information about what Dozer has been labeled:

"Dozer is usually somewhere between 80 and 87 pounds (he should be 80 lbs at healthy weight) and stands about 26 inches at the shoulder. Though it’s hard to tell in the photos, Dozer’s body is really not very wide or muscular; it reminds me more of a Lab’s body than a pit bull’s body.When we adopted him (as a little puppy), the shelter said he was a purebred pit bull, and told us he wouldn’t get larger than about 50 lbs. We went for a second opinion when he was about 8 months old, and a pit bull rescue group worker said he was not a pit bull at all—he was a Dogo Argentino. Though everyone at our vet office has generally acknowledged he’s a pit bull mix… Another vet .. said he was obviously a 'Lab mix of some sort.' And one time, a really clueless stranger at Petsmart marveled at our 'white Rottweiler.' "

And Dozer’s DNA results? According to his Mars Mixed Breed Panel test “Dozer ancestry contains distant traces of American Staffordshire Terrier, Bull Terrier, Bulldog, and Dalmatian. There are also faint signals from other breeds which are not strong enough to identify.” And yet in some cities in our country Dozer would be banned because he might possibly have some physical characteristics matching those of a pit bull.

Another outcome will be to develop a test using photos and DNA results. This test will then be taken by animal control officers, dog wardens, veterinarians and techs, animal rescue workers, and lay people. The test will be on one’s ability to determine the predominant breed of a dog based on the physical characteristics (photos) alone. Unlike the “Find the Pit Bull” tests which give you a 50% chance of guessing correctly, this test will ask the subject to determine the dogs’ predominant breed. We will then analyze the results looking at consistency associated with training, background, education level, etc. versus the DNA results.

If you would like to participate or have further questions about the study, please contact us at helpfido@gmail.com.

2 comments:

However, while we've all enjoyed playing guess the mutt over the years, it really is just a guess. A dog's physical appearance is just a vague indicator of possible ancestry.

I await some actual evidence and publications around the DNA tests before deciding upon their validity. I've seen the raw data from Mars and it's not enough to be conclusive - the sample sizes were too small and the error margin was too high - and that was for purebreds.

Right now, my gut is that they are unreliable and a waste of time and money.

Here's why.

1. All dogs are genetically very close, much like humans.2. Dogs are very plastic, ie, they mutate very readily also much like humans.3. Breeds are just ethnic subsets within a species, most of them very new. Can you tell a German from an Irishman strictly on DNA? A Norwegian from a Swede? I doubt it. Can you tell a German/Irish/Norwegian cross? I doubt that, too.4. When you think about expressed and recessive genes, it gets more complicated. Could I ID a Chow Chow or Shar Pei? Possibly, due to the black tongue. A Dal for urate crystals and spots. A Dachshund or Basset Hound for dwarfism (both are true dwarves) and so on.

Could I tell an Irish Water spaniel from a Poodle cross? A Brussels Griffon from an English Toy spaniel or Pug cross? Not likely.

If you have to send a photo, a quick look at Dozer would automatically include Dalmatian and Bulldog - two of the progenitors of the bully types. The AmStaff and Bull terrier findings are suspect since they also should show up as Dal and Bulldog types. If no photo is required, that's a pretty good analysis, much better than expected based on both companys' disclaimers and their own accuracy numbers.

In other words, I'm not saying it's impossible but it's highly unlikely that these tests, especially for mixed breeds, are accurate. I await more info.

I think you bring up some excellent points. The main being that that "a dog's physical appearance is just a vague indicator of possible ancestry. Also, I completely agree that we need some published data by Mars and the others running these tests in peer reviewed journals. We actually ran the study idea by some canine geneticists who are doing some of their own research in the same arenas and they expressed some of your same points. The mixed breed panel test is actually quite different from the pure-bred test in that one dog's DNA is cast against the entire spectrum of possible matches, rather than just one pure breed set of data. And then the result is put through computer algorithms to further verify the chance of the results being correct. The tests in general are still very new and may well be unreliable. We have had some very, um, confusing results submitted to us.That being said, we still feel that they offer some insight into the complicated idea of breed specific legislation. As you know, some cities are even using DNA testing to determine if a dog is "ban-able." However, I still feel that the testing used for "fun" or in the way that our project will use it - can provide some useful information. At least I hope so.

*Ways to help sheltered and rescued pit bulls:

1. Volunteer to help local spay/neuter efforts.2. Supply hand-outs to help educate the public about pit bulls.3. Volunteer to help update a shelter's website.4. Donate a Karunda bed so dogs can sleep better.5. Donate tuff toys like large kong balls.6. Volunteer to walk dogs that are waiting for homes. *copied with permission from badrap-blog.blogspot.com